In his greenhouse, Ragan Callaway pits spotted knapweed plantings (left) against native Montana grasses (right), trying to outwit the weed's chemical weaponry. Brian Smale Wayne Slaght is a rancher.

Spotted knapweed (Centaurea stoebe) is a biennial or short-lived perennial native to Eastern Europe. It was introduced into the U.S. in the 1800’s as a contaminate in seed. It is an extremely ...

Orange Jerusalem renamed Orange Ariel, evoking an alternate biblical name for the capital and the vivid color of the slain ...

"One of the species that we've battled a lot is called spotted Knapweed also called Start thistle. It's a species that actually creates kind of an environment that other species won't grow in.